One idea of personalized cancer therapy is to identify specific subgroups of cancer patients that will benefit from specific therapeutic strategies. Recently, the NCI has proposed a new research emphasis to design rigorous and innovative research strategies to solve specific problems and paradoxes in cancer research. This research proposal addresses an NCI emphasis: that is how do the proteins that direct life span, at least in some part, affect the molecular mechanisms of cancer development. In addition, can a greater understanding of the mechanisms that direct aging be used to enhance the prevention and/or treatment of cancer? In this regard, it is proposed that the CLOCK/NAD+/SIRT3 axis plays a role in the prevention of damage for IR the deletion of the genes in the axis in mice should result in the creation of new murine models for the investigation of human illness, including human malignancies, that have a strong genetic connection to aging or the genes in the CLOCK/NAD+/SIRT3 axis. In this regard, our preliminary results suggest that circadian CLOCK proteins coordinate mitochondrial metabolism, in part via the modulation of protein acetylation, including MnSOD, to metabolic and oxidative pathways with circadian rhythms. Based on our results, and those or others, it is hypothesized that the CLOCK/NAD+/SIRT3 signaling axis protects against IR-induced damage, cytotoxicity, genomic instability, and carcinogenesis, through the regulation of MnSOD mitochondrial detoxification activity via deacetylation of K68 and K122. In addition, it is proposed that this axis is a potentil molecular axis to sensitize tumor cells to cytotoxic strategies, including IR.